Method of making a connector with hard particle lining



Aug 30, 1955 l. F. MATTHYSSE 2,716,275

NNNNNN OR METHOD F MAKING A CONNECTOR WITH HARD PARTICLE LINING Irving Frederick Matthysse, New York, N. Y., assignor to Bumdy Engineering Company, Inc., a corporanon of New York Ori al application August 7 1948 Serial No. 13,023. liisided and this application June 27, 1951, serial No. 233,908

2 Claims. (Cl. 29-459) My invention relates to connectors having tubular bodies that may be used to splice wires or cables, and more particularly to the method of making connectors that are indented to the wire and locked thereto by hard particles that key the connector to the wire, and is a d1v1- sion of my application, Serial No. 43,023, tiled August 7, 1948, now Patent No. 2,576,528.

Hitherto, in actual practice, such devices have employed chromium, Nichrome or non-metallic particles applied to the inside surface of the tubular connector, as is illustrated in Patent No. 2,149,209. These particles produce una satisfactory results, where the connector is used to transmit current or where the metal of the particles is diiferent from that of the connector or Wire, for in the lirst case chromium, Nichrome and hard non-metallic particles are highly resistant to the ow of current, and in the latter case electrolytic corrosion may set in.

Accordingly, the primary object of my invention 1s to provide a suitable keying-in material that may be secured to the inside of a hollow connector to form a lining which will more nearly approach the conductivity of the metal forming the connector body, than particles previously used for this purpose, and which additionally Will not cause electrolytic corrosion.

I have found that I can solve the problem of conductiivity and electrolytic corrosion when copper connectors and wires are employed by alloying copper with a small amount of beryllium. Unfortunately the alloy when sprayed does not harden suthciently to warrant extensive use as a keying material. Since the aforesaid alloy may be made exceptionally hard, another object of my invention resides in providing a method of hardening the particles secured to the inside of tubular connectors.

Copper connectors of the splicing type are considerably Worked during the manufacturing process, and indention of the connector walls for securing the connector to a wire requires readily malleable material. This can be accomplished by heating and annealing the copper connector thereby softening the walls.

A still further object consists in providing a method whereby the connector body can be softened and the alloy particles hardened.

I have further discovered that by applying the molten alloy inside the connector Walls, that I can thereafter harden the alloy and soften the connector walls in one operation by simultaneously heating the connector with the alloy particle lining.

Other objects consist in providing methods of applying the alloy particles to the connector in a manner Which will be least expensive, and readily adaptable to mass production methods.

I accomplish these and other objects and obtain my new results as will oe apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

Fig. l is a side elevation of a connector splice having United States Patent O "ice an inner particle lining made in accordance with my invention.

Fig. 2 is an enlarged cross-sectional view taken in the plane 2--2 of Fig. l.

Fig. 3 is a side elevation, partly in section of my connector splice secured to a conductor.

Fig. 4 is a cross-sectional View of the same taken in the plane 4 4 of Fig. 3, showing the indenting dies in position.

Fig. 5 is an enlarged longitudinally sectioned and fragmentary view of the connector wall to which the particle lining has been secured with the conductor in position and before indentation.

Fig. 6 is a similar view after indentation.

In the drawings, reference numeral 10 designates aV tubular body or sleeve having an internal hard particle lining 11. The diameter of the internal bore of the sleeve must be sucient for clearance over the Wire 12, allowing for the thickness of the particle lining. The Wire stops 13 and 14 may be formed in the bore to prevent inserting the wire too far, by indenting the sleeve as at 15. Each entrance 16, to the inside of the sleeve is well chamfered or rounded as at 17, to prevent nicking the Wire and to prevent breakage due to possible vibration. The chamfer 17-A on the outside is to prevent snag ging when the wire and sleeve are pulled over a crossarm of a pole.

The compressed portions or indentsv 18, are producedl by compressing dies 19 and 20, shown in Fig. 4, which may leave a small flash 21. As a result of these indentations the surface of the wire takes on a wavy form as seen at Fig. 3, thereby increasing the grip of the sleeve on the Wire.

In Fig. 5, there is illustrated an enlargement of a portion of a longitudinal section of the sleeve with the wire inserted in place. The particles are preferably formed with sharp points, indicated by the roughness of the liner 11, on the sleeve 10. Both the inside of the sleeve 23, and the outside of the wire 24, may be smooth. The hard particles forming the liner are secured to the inside wall by a number of methods hereinafter explained. After compression this enlarged longitudinal section appears as in Fig. 6, in which the individual hard particles 25, are seen to have impressed themselves into the softer surfaces of the sleeve and Wire, each particle preferably acting as a key to prevent any slipping of the wire relative to the sleeve under longitudinal tension. Thus with a suitable arrangement or indentations each having the proper amount of compression or depth, the wire will not slip under tension, and Will fail only when the ultimate strength of the wire is approached and preferably outside the connection.

Particles made of copper containing from 1% to 2% of beryllium is satisfactory. I have found that 98% copper and 2% beryllium is preferred and that an excess of 2% of beryllium does not materially add to the hardness of the alloy ot justify the expense of the added quantity of beryllium and will lower the current carrying capacity of the alloy. The 2% alloy has a current carrying capacity, for equal temperatures, of approximately one-half that of pure copper and approximately equal to the current carrying capacity of material customarily used to make electrical connectors. On the other hand, the 2% beryllium-copper alloy has an electrical conductivity of over lifteen times that of Nichrome, now used as a particle lining.

The 2% beryllium-copper alloy has a Rockwell hardness of 15 N 72 compared with l5 N 40, the Rockwell hardness of hard drawn copper wire. Thus the alloy particles will penetrate copper wires and, of course, the much softer pure copper, without difviculty. Irregular and pointed particles suitable for a sleeve liner may be obtained from this material by spraying the molten alloy with a eonventional'metal spraying gun anddireeting this spray into the barrel of the connector sleeve causing the particles to adhere when they strike the inner surface of the slee've.- Thereafter' the p''rtiele lining is treated a heat treating process which simultaneously increases the hi'in'ss of the lining 'vvhile annealing the copper sleeve to the correct degreeof malleability. fsui'table temperatui'e is 'approitiniately '650 F., held tor about `one hour, and cooled slowly thereafter. Y

Mather manca of applying 'the partie-ies to the inside of ya sleeve cion's'i'st's vin coating thereon a thermosetting material such as a silicon resin or any suitable thermo'- pl'stie adhesive. In 'suchmeth'o'd the particles may be applied to 'the e'oatjed surface of the sleeve; land the combined sleeve, adhesive, and particles heat treated as afore-v said. Thus, in the latter case the adhesive may be softened under the he'at While in the former case it is lhardcned by the heat while the particles are in contact therewith', lthis retainingv the particles when cooled.

vStill another 'method comprises-'a novel process for manufacturing paitiele's of 'the proper 'size and shape, and hardening theni lv'vhile in their yloose form'. This can be accomplished by spraying the molten alloy into Cold water after'whieh the 'particlesmay be collected, and sorted by si'eving'l to Aobtain the desired range of particle siie. The particles may then be hardened by the aforementioned heat-treatment, and applied t'o the inner srfaceY of the sleeve: This may be advantageous where Vit is desired to heat the sleeve to a different temperature than that needed tol harden the particles. The process dislosedin Patent 2,683,095 may be used for this purpose.

It Will be thus seen that by hardening the keying particles after 'they ae formed; the process of making particles and the materials for them need not ber'es't'ric'ted tothose processes and materials Which produce hard particles. A

[have thus described my invention, but I desire it understood that it is not conned to the particular forms or uses shown and described, the same being merely illus-l trative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalit's'coing within the scope of the appended claims, and by means of which, objects of my invention area'tt'ained and 'new resultsc'cbmpli'sle'd,

as it is obvious that the particular embodiments herein shown and described are only some of the many that can an adhesive to the inner lvvall of -the tubular body at ak temperatnre which n'o't aiect 'the hardness of the beryllium coppei parti'c'le's.

2. The method 'of claim l, wherein the sprayed particles are sieved to obtain the proper size for use with` the Connector Body.

lReferences Cited in the ile of this patent v l UNiT STATES PATENTS 'MOIC OC. 13; 1931 1,898,487 Hurley Feb. 21; 1933 2,187,348 HOdSl June 16, 1940 2,244,109 Klein Juno 3; 1941 2,365,208 MOITS De'C. 19, 1944 2,464,437 DShI' Milf. 15, 1949 2,627,649 

